HY3844 Просмотр технического описания (PDF) - Unspecified

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производитель

HY3844

Fixed Frequency Current Mode PWM Controller.

Unspecified 

HY3842/43/44/45

DESCRIPTION

The HY3842D-N/3843D-N/3844D-N/3845D-N, are fixed frequency

current mode PWM controller. They are specially designed for OFF−Line and DC to DC

converter applications with a minimal external components. Internally implemented circuits

include a trimmed oscillator for precise duty cycle control, a temperature compensated

reference, high gain error amplifier, current sensing comparator, and a high current totem pole

output ideally suited for driving a power MOSFET. Protection circuitry

includes built under voltage lockout and current limiting.

The HY3842D-N, HY3844D-N, have UVLO thresholds of 16 V (on) and 10 V (off).

The corresponding thresholds for the HY3843D-N/3845D- N are 8.4V (on) and 7.6V (off).

The HY3842D-N, HY3843D-N, can operate within 100% duty cycle. The HY3844D-N,

HY3845D-N, can operate within 50% duty cycle.

The HY384XD-N have Start-Up Current 0.17mA (typ).

PIN CONNECTION

(TOP VIEW)

FEATURES

• Low Start-Up and Operating Current

• High Current Totem Pole Output

• Under voltage Lockout With Hysteresis

• Operating Frequency Up To 500KHz

BLOCK DIAGRAM

(toggle flip flop used only in HY3844, HY3845)

Absolute Maximum Ratings

Characteristic

Supply Voltage (low impedance source)

Output Current

Input Voltage (Analog Inputs pins 2,3)

Error Amp Output Sink Current

Power Dissipation (TA=250C)

Storage Temperature Range

Lead Temperature (soldering 5 sec.)

Symbol

VCC

IO

VI

ISINK (E.A)

PO

Tstg

TL

Value

30

±1

−0.3 to 5.5

10

1

-65 to150

260

Unit

V

A

V

mA

W

oC

oC

1

www.hooyi-semi.com

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